Yixian Tian is a dramatic canyon and pinnacle site located off Lanyu. The topography features a narrow channel cutting through the reef, creating a signature slot formation. Divers typically explore depths between 15 and 40 metres, with an average depth of 25 metres. Visibility ranges from 20 to 30 metres, providing clear sightlines along the canyon walls. The site is subject to moderate currents that can shift quickly, requiring intermediate skill levels. Access is by boat only, and divers should remain aware of surge and swell during entry and exit procedures. Species recorded around this area include sea kraits, clown triggerfish, regal angelfish, and various nudibranchs.

Lungmenkang is a coastal site on Lanyu, Taiwan, featuring a combination of natural reef and artificial reef structures. The site is suitable for beginners, with depths ranging from 5 to 13 metres and an average depth of 10 metres. Visibility is high, typically between 30 and 50 metres. Divers access the site from the shore, though the entry requires careful planning due to surf and shore break conditions. Moderate currents are present, and divers should remain alert for boat traffic. Water temperatures remain between 25 and 30 degrees Celsius throughout the year. Species recorded around this area include sea kraits, various wrasses, surgeonfish, and triggerfish.

Sitiaogou is a deep reef and canyon system located off Lanyu, Taiwan, characterised by complex topography and strong currents. This site is strictly for advanced divers, with depths ranging from 25 to 42 metres and an average depth of 30 metres. Divers experience high visibility between 30 and 50 metres in water temperatures of 25 to 29C. Due to the strong currents and overhead environments within the canyons, boat access is required for all entries. The site is suitable for drift diving and night diving, though navigation is demanding. Divers should plan entries around slack tide to manage the flow through the canyon structures.

Green Field is a boat-access dive site off Lanyu, Taiwan, characterised by shallow reef terrain. The site features a wall that extends to 70 metres, requiring divers to monitor their depth gauge closely. Conditions are variable, with strong currents that can shift quickly and push divers off the reef. Marine life recorded at the site includes wrasses, groupers, Pacific Orange-spine Unicornfish, rock cod, Powder-blue Surgeonfish, Striped Surgeonfish, Bird Wrasse, Moorish Idol, Indo-Pacific Sergeant Major, hawkfish, Lined Bristletooth, and snails. Due to the potential for strong currents and the depth of the wall, this site is suitable for intermediate divers who possess strong buoyancy control.

Sankuaishih is a marine dive site off the coast of Lanyu, Taiwan, featuring a shallow reef top that transitions into a wall and drop-off. The topography descends from 5 metres to depths exceeding 30 metres, with an average depth of 20 metres. Divers encounter moderate currents that require solid buoyancy control. Visibility is variable, ranging from 20 to 50 metres. Access is by boat only, and the site is suitable for intermediate divers. Night diving is available through local operators. Due to the potential for strong currents and boat traffic, divers should maintain awareness of their surroundings and plan their dives to work into the current.

Ma'an Reef is a current-swept site located off Lanyu, Taiwan, accessible only by boat. This advanced dive site features sharp coral and rock formations requiring precise buoyancy control. Divers experience strong currents and significant surf, necessitating careful timing for boat approaches. Visibility is high, ranging from 30 to 50 metres, with water temperatures between 25 and 30 degrees Celsius. Due to the challenging conditions, including deep water and strong currents, this site is suited for experienced divers. Species recorded around this area include sea kraits, regal angelfish, clown triggerfish, nudibranchs, and various wrasses and surgeonfish.

Badaiwan is a deep-water site off Lanyu featuring a combination of wreck and canyon topography. The site lies at depths between 38 and 41 metres, with the wreck structure itself located between 17 and 22 metres. Visibility is high, ranging from 30 to 50 metres, allowing for clear views of the canyon walls and wreck during descent. Due to the depth, overhead environments, and potential for moderate currents, this site is suitable only for advanced divers. Boat access is required. Divers should monitor their depth closely and avoid entering enclosed internal areas of the wreck. Guided tours are recommended to navigate the canyon layout effectively.

Guandongshi is a reef and wall site located on the outer reef of Lanyu. The topography features a wall dropping from 15 to 45 metres, with an average depth of 30 metres. This site requires boat access and is suited for intermediate divers with drift-diving experience. Conditions include strong, shifting currents and visibility ranging from 20 to 50 metres. Divers should be aware of sharp coral and rock edges, necessitating good buoyancy control. Due to the strong flow, timing descents for slack water or the early incoming current is recommended. An Advanced Open Water certification or equivalent is required to navigate this site safely.